Starting Tuesday, November 12, Sonoma County drivers will experience smoother and safer traffic flow at the SR-116/121 intersection, as Caltrans shifts to a temporary roundabout. The current four-way stop will be replaced by the roundabout by 5:00 a.m. as part of an ongoing project to improve traffic flow, reduce congestion, and increase safety. While the final roundabout, complete with additional lanes, bike lanes, and sidewalks, won’t be finished until late 2025, this temporary setup will help traffic move more efficiently in the meantime.
Expect nighttime lane closures from 9 p.m. to 5 a.m. on Friday, Nov. 8, and Monday, Nov. 11, but at least one lane will remain open in each direction. The lane connecting northbound Route 121 to eastbound Route 121 will also reopen, helping to alleviate congestion. However, be aware that this lane will close again in Spring 2025 for further pedestrian improvements. Drivers are encouraged to adjust to the new layout and drive cautiously to help ensure a safer commute for all.